What is Atomic Absorption Spectroscopy (AAS)

Elemental analysis using atomic
adsorption spectroscopy

What is atomic adsorption spectroscopy?

Atomic adsorption spectroscopy (AAS) is used to measure the concentration of metallic elements in different materials. As an analytical technique, it uses electromagnetic wavelengths, coming from a light source. Specific elements will absorb these specific wavelengths differently, giving a picture of what concentrations of a specific element there is in the material being tested.

Using AAS, you can measure for a specific element in a material, based on the amount of light absorbed at a defined wavelength, which corresponds to the known characteristics of the element under test.

Compairson-of-atomic-spectroscopy-techniques-fig-3
Group of young researchers analyzing mineral chemical data in the laboratory
Quantification-fig-2

What is atomic adsorption spectroscopy?

Atomic adsorption spectroscopy (AAS) is used to measure the concentration of metallic elements in different materials. As an analytical technique, it uses electromagnetic wavelengths, coming from a light source. Distinct elements will absorb these wavelengths differently, giving a picture of what concentrations of a specific element there is in the material being tested.

Using AAS, you can measure for a specific element in a material, based on the amount of light absorbed at a defined wavelength, which corresponds to the known characteristics of the element under test.

Why should I use atomic adsorption spectroscopy?

AAS provides a high degree of accuracy, with results normally produced in a range of 0.5-5% accuracy. It is a highly sensitive test method and, depending on the material under test, can measure as low as parts per billion (µg/kg) .

This high sensitivity makes it ideal for medical and pharmaceutical applications where it can be used to detect trace levels of toxins. It can also be used in industrial applications such as mining, where it is often used to test rocks for suitability for mining.

AAS can be used to determine concentrations of over 65 elements using a relatively simple process, requiring minimal training to conduct sample analysis. It also allows for a high sample throughput while being inexpensive compared to other analytical techniques. This combination of benefits makes the technique attractive from a commercial perspective.

When should I use atomic adsorption spectroscopy?

Atomic absorption spectroscopy has different laboratory and testing applications in industrial, clinical and research settings, as a crucial component in various processes including quality control, toxicology and environmental testing.

As a method, AAS can analyse the content of certain metals in various materials. For example:
• In environmental testing, it can measure the concentration of various elements in rivers, drinking water and seawater.
• In the food and drink industry, it can measure various concentrations of elements in wine, beer and fruit drinks and test for types of contamination in food.
• For pharmaceutical companies, AAS can determine the minute quantities of catalyst materials used in the manufacture of drugs, and for other impurities.
• In industry, there are different raw materials requiring examination and analysis to check they have sufficient amounts of certain major elements, and that there are not too many impurities, some of which could be toxic.
• In mining, AAS can test for the concentration of valuable materials before excavation operations.
• AAS is used in agriculture, to analyse plants and soils for mineral content.
• Metals and other substances can have a bad effect on oil and gas, which is why the petrochemical industry uses AAS.
• The technique also supports critical testing in the nuclear industry, where there could be potentially hazardous elements in the output of waste and water.

When should I use atomic adsorption spectroscopy?

Atomic absorption spectroscopy has different laboratory and testing applications in industrial, clinical and research settings, as a crucial component in various processes including quality control, toxicology and environmental testing.

As a method, AAS can analyse the content of certain metals in various materials. For example:
• In environmental testing, it can measure the concentration of various elements in rivers, drinking water and seawater.
• In the food and drink industry, it can measure various concentrations of elements in wine, beer and fruit drinks and test for types of contamination in food.
• For pharmaceutical companies, AAS can determine the minute quantities of catalyst materials used in the manufacture of drugs, and for other impurities.
• In industry, there are different raw materials requiring examination and analysis to check they have sufficient amounts of certain major elements, and that there are not too many impurities, some of which could be toxic.
• In mining, AAS can test for the concentration of valuable materials before excavation operations.
• AAS is used in agriculture, to analyse plants and soils for mineral content.
• Metals and other substances can have a bad effect on oil and gas, which is why the petrochemical industry uses AAS.
• The technique also supports critical testing in the nuclear industry, where there could be potentially hazardous elements in the output of waste and water.

How to select the right AAS instrument for the job?

AAS can be used to determine metallic elements in environmental, pharmaceutical, chemical, petrochemical and food and beverage applications. Depending on the application, technicians can use flame (FAAS), graphite furnace (GFAAS) or hydride generation AA (HGAAS).

FAAS, which is the original and most common type of AAS, uses flame to atomise samples in the instrument. In applications, where the testing is for low numbers of elements in a material in substantial concentrations, FAAS is an effective analytical technique. When sample size is limited or the analyte is present in low concentrations, GFAAS or GHAAS techniques are more suitable. SciMed supplies a range of flame, graphite furnace and hydride generation AAS instruments, view the full range of AAS instrumentation below.

How do you perform atomic adsorption spectrometry experiments?

Sample preparation is as simple as weighing a fixed amount of the sample and diluting it into a solution before introducing it to the AAS instrument, which will then vapourise the sample before atomising it. There are two ways to atomise the sample:
• Flame aspiration, which involves transferring the a solution into a flame, where most of it is vapourised.
• Electrothermal atomisation, where the sample is placed in a hollow graphite tube, and, once heated, is vapourised completely.

Once atomised, an electromagnetic beam is passed through the sample, which will absorb some of this electromagnetic radiation. This absorbance will be measured by the AAS and results displayed on the screen, which can then be used to determine concentrations using the Beer-Lambert law; A = εcl.
• A: Absorbance
• ε: Molar absorptivity
• l: Light path length
• c: Concentration

One of the most important aspects of AAS experiments is using reliable analytical  standards to create a calibration curve, are essential to help determine the concentration of the element under test by comparing to results for known concentrations. To help with this, SciMed supplies certified standards for a variety of analytical techniques, including AAS.

What to do next?

To view SciMed’s range of atomic adsorption spectroscopy instrumentation, alternatively, to speak to one of SciMed’s team about how you can use AAS



Contact Us

* Live chat opening hours Mon – Fri 9:15 to 16:30 (UK Time)

Global Brands, Local Support